The revelation of last season, the Boone, incorporates Trek’s IsoSpeed Decoupler, the pivot point at the junction of the seat tube, top tube and seatstays that allows the seat tube to flex more freely. Besides more comfort, what this means is the ability to stay seated and pedal efficiently more often on a rough course.
The Boone 5 Disc brings this bump-absorbing design to a more attainable price, with hydraulic Shimano 105 and in-house Bontrager components and tubeless-ready wheels equipping the full carbon frameset.
It’s difficult to overstate how drastically the IsoSpeed Decoupler flattens choppy sections of a course. While your tyres are still doing the lion’s share of the work keeping traction, the frame’s ability to suspend your body keeps the engine better engaged.
While the Decoupler makes for a great visual talking point, the fork is perhaps the more impressive engineering feat, as the long forward sweep takes the edge off but the tucked-back dropout placement keeps the geometry in check.
As a roadie who can race like a bit of a squirrel (hello, course tape!), I found the Boone 5 Disc to be an effective sedative that often made me faster because I could focus more on steady pedalling and less on reacting to being rattled around.
Complementing the smooth-is-fast damping is the bike’s geometry, with a low bottom bracket (68mm drop) keeping your centre of gravity down in the bike.
The IsoSpeed Decoupler allows the entire seatmast and seat tube to flex as one big bow
Trek’s attention to detail on this bike is readily apparent, with smartly designed internal routing, an über-wide BB90 bottom bracket, an integrated chain keeper, a gel-padded chain protector, and a 15mm front thru-axle that ensures your disc won’t rub, no matter how many times you smash your front wheel against that barrier.
The top tube sits a little lower than an old-school horizontal tube and dives toward the back, but dismounts at speed with a hand on the top tube are still very stable.
The seatmast has a 10cm range of seat height. Our 56cm tester, for instance, has a 71-81cm saddle height range. With a little carbon paste the seatmast hasn’t budged, despite being subjected to scores of poorly executed remounts.
One huge highlight of this bike is that tubeless-ready wheels come as standard. Most bikes at this price point come with clinchers. However, the tyres specced are standard clinchers, meaning you have to pony up for the rim strips and tubeless tyres. Aside from the tubeless capability that makes the bike more race ready than its innertube-equipped friends, the Bontrager TLR wheels aren’t impressive — they’re heavy and I easily knocked the rear out of true in the first race.
Tubeless-ready wheels? Sweet! Now, come on, Trek, and seal the deal (or give us a deal on the seal?) with tubeless tyres instead of clinchers
The hydraulic Shimano brakes are excellent, offering all the power and modulation you could possibly need. Coming from cantilever brakes in dry conditions, the huge difference is laughable. And in wet conditions, comparing them to cantilevers is like comparing air travel to walking; it’s not really fair.
Hydraulic brakes do add a bit of weight, of course, mostly in the rotors, calipers and levers, as the lines themselves are lighter than steel cables. Combined with the piggish wheels, the bike on the whole is on the heavier side at 19.42lb / 8.81kg.
For me, the weight penalty of discs is a price I am happy to pay in cyclocross. For road bikes, I love the feel of discs but I still lean towards rim brakes (the bikes and wheels are lighter, I want to swap wheels with what I have in my garage, and so on). But for cyclocross, it's no longer a question: discs are a huge advantage over the noise-makers parading as cantilever ‘brakes’. There's no going back for me.
Bottom line: you can’t really go wrong with the Boone 5 Disc frameset, Shimano hydraulic brakes and, for the price, the Shimano 105 group. The wheels, while generally unimpressive, are tubeless-ready and therefore just about ready to race right out of the box.